Unmanned Aerial Vehicle Flying Qualities Evaluation Method Research Based On Task

Modern fixed-wing UAV has been widely used in various types of military/civilian missions, showing huge military and economic value. At this stage, UAV design emphasis on flight performance and mission capability with no attention to UAV flying qualities. In design process, people always use piloted flying qualities which is cut out relevant part of sense as a guide, which will cause deviation of design target. Therefore, research on UAV flying qualities has important theoretical significance and engineering value.This paper takes air-to-air refueling task as an example to study two methods on evaluating UAV flying qualities. 1) Given closed loop longitudinal mode range, eigenstructure assignment method is used to design command tracking flight control law. RMS contour plots which are based on analysis in frequency domain of linear model intuitively reveals wind resistance ability in different longitudinal mode when UAV is affected by continuous atmospheric turbulence. But RMS cannot predict worst case because RMS is a 2H norm in essence which represents ‘average’ case, so we choose H? norm. 2) Combining mixed sensitivity optimization method and the method in calculating H? norm of continuous atmospheric turbulence/command tracking error which is based on frequency domain, we construct H? norm contour plots in closed loop longitudinal tracking mode plane. The contour plots directly and quantitatively reflect the relationship between UAV flying qualities and flight performance. Then it is verified by simulation by ?.synthesis. Results show longitudinal mode required by air-to-air refueling task is different from piloted flying qualities. In a result, UAV flying qualities specification should consider wind resistance ability in category A flight phase to increase UAV’s trajectory/attitude tracking ability.